function CrackLife

global glb

mu=glb.test.mu;
sigma=glb.test.sigma;
Num=glb.geom.N;

NN=power(10,normrnd(mu,sigma,1,2*Num));

glb.crack.N=min(NN)*1;
glb.crack.dN=min([min(NN)*0.005,1000]);
glb.crack.life=NN;